Electrocardiography is a common, painless medical technique that records the electrical activity of the heart as an electrocardiogram or ECG (also referred to as an EKG). The resulting waveform is a graphical representation of the electrical activity of the heart as a function of time. The waveform may be viewed on a monitor or printed on a material, usually paper, which is commonly referred to as an “ECG strip”. From an analysis of the ECG strip, various physical and biological properties of the heart may be determined or estimated. For example, one can assess the rate at which electrical impulses are moving through the heart and the rate and regularity of heartbeats. An analysis of the waveform can also reveal signs of damage to the heart or indicate problems with the electrical conduction system.